The present invention relates generally to bicycle hub axles, and more particularly to a bicycle hub axle having a dynamo thereon.
Referring to FIGS. 1-2, to prevent the necessity of batteries, bicycles often employ some type of electricity generating device to power a lamp, such as a headlight, taillight or the like. In the past, a dynamo 106 disposed on the axle 108 and inside the hub shell of the bicycle has been used to generate the necessary power. However, those skilled in the art have encountered difficulties in assembling the components of the axle and dynamo.
The axle 108 includes a groove 112 that extends axially along both a smaller diameter portion 114 and a larger diameter portion 116 of the axle 108. A cone 118 is threaded onto the larger diameter portion 116 and abuts a nut 120 that holds the stator yoke 122 of the dynamo 106 in place. A spacer 124 is fitted on the axle 108 behind the cone 118. The spacer 124 includes a single tongue 126 extending downwardly into an opening in the center thereof. The tongue 126 is fitted in groove 112 to prevent the tongue 126 from rotating about the axle 108. A connector housing 128 having an electrical connector 130 therein is fitted on the axle 108 behind the spacer 124. The electrical connector 130 is electrically communicated to the dynamo 106 by a wire 131. An insulation plate 132, ground plate 134 and lock nut 136 finish the assembly and lock the components onto the axle 108.
One of the problems encountered with the prior art is that electrical wire 131 is often damaged during assembly. For example, because of the configuration of the axle 108, the groove 112 has to be machine cut. Machine cut grooves often have burs. A bur can cause two problems. First of all, it may make it difficult to set the cone 118 in the proper location. Secondly, the bur can cause damage to the electrical wire 131.
Another problem is caused by the spacer 124. The tongue 126 on the spacer 124 is typically small and can easily be broken off in groove 112. When this happens, the spacer 124 is free to rotate about axle 108, which often happens when lock nut 136 is tightened against the ground plate 136. Rotation of spacer 124 can cause wire 131 to be damaged and even break.
Accordingly, it is desirable to provide a hub axle having a dynamo thereon that is easy to assembly, that minimizes problems with setting the cone in the proper location and that minimizes occurrences of electrical wire breakage.
In accordance with a first aspect of the present invention there is provided a bicycle dynamo hub axle having opposite ends that includes a smaller diameter portion located at one end of the axle, and a larger diameter portion defining an axis. The smaller diameter portion has a smaller diameter than the larger diameter portion, and the larger diameter portion has at least two grooves defined therein that extend in a direction non-parallel to the rotational direction of the axle. In a preferred embodiment, the larger diameter portion includes a stepped portion extending radially outwardly therefrom and a portion of the grooves extends into the stepped portion. The larger diameter portion includes a groove inner diameter that is larger than the diameter of the smaller diameter portion.
In accordance with another aspect of the present invention there is provided a bicycle dynamo hub axle assembly that includes an axle having opposite ends, a smaller diameter portion located at one of said opposite ends, and a larger diameter portion, an electricity generating device disposed on the larger diameter portion of the axle, a bearing race disposed on the larger diameter portion, an electric wire extending from the electricity generating device, through one of the grooves and through the bearing race, a spacer disposed on the larger diameter portion, and a lock nut disposed on the smaller diameter portion for securing the bearing race and the spacer in position. The smaller diameter portion has a smaller diameter than the larger diameter portion and the larger diameter portion has at least two grooves defined therein. The larger diameter portion also includes a stepped portion extending radially outwardly therefrom. The spacer has an opening defined therethrough, and has at least one tongue extending inwardly into the opening. The tongue is received in one of the grooves, thereby preventing the spacer from rotating.
In accordance with yet another aspect of the present invention there is provided a bicycle dynamo hub axle assembly including an axle having opposite ends that includes a smaller diameter portion located at one of the ends and a larger diameter portion located inboard of the smaller diameter portion, a washer, an electricity generating device disposed on the larger diameter portion of the axle, a cone having a non-threaded interior disposed on the larger diameter portion, a spacer disposed on the larger diameter portion, an electric wire extending from the electricity generating device, and a lock nut disposed on the smaller diameter portion for securing the cone and spacer in position. The smaller diameter portion has a smaller diameter than the larger diameter portion and the larger diameter portion has four grooves defined therein that extend in an axial direction. The grooves are spaced circumferentially around the larger diameter portion approximately equidistance apart. The larger diameter portion also has a stepped portion extending radially outwardly therefrom. A portion of the grooves extends into the stepped portion. The grooves also include an open end opposite the portion of the groove that extends into the stepped portion. The larger diameter portion also includes a recess defined therein. The washer is disposed in the recess and the opening is formed transversely therethrough at a location adjacent one of the grooves. The cone is disposed outboard of the electricity generating device and the washer and has four protrusions extending axially inwardly therefrom. The four protrusions are received in the portion of the grooves defined in the stepped portion, thereby preventing the cone from rotating on the axle. The spacer has three tongues that extend radially inwardly into an opening defined therethrough. The tongues are received in three of the grooves defined in the larger diameter portion, thereby preventing the spacer from rotating. The electric wire extends through the opening in the washer throughone of the grooves and through the cone.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.